1. Field of the Invention
The present invention relates to a robot hand for transporting a work unit that includes a plate-shaped work supported by an annular frame via an adhesive tape.
2. Description of the Related Art
When a plate-shaped work is processed by a processor, an adhesive tape is affixed to one side of an annular frame whose central portion is open first. Then, the plate-shaped work is affixed to an adhesive side of the adhesive tape exposed from the opening portion of the annular frame, thus forming a work unit. A processor for processing a plate-shaped work making up such a work unit includes at least a cassette, robot hand, temporary storage table, processing table, processing means and cleaning means. The cassette accommodates the work unit. The robot hand unloads the work unit from and loads it onto the cassette. The temporary storage table temporarily stores the work unit. The processing table holds the work unit. The processing means processes the work unit held by the processing table. The cleaning means cleans the processed work unit.
A conventional robot hand 10 shown in FIG. 5 has a mounting surface 11 whose tip side branches into two parts and to which a work unit is mounted. An anti-fall hook 12 having a surface more elevated than the mounting surface 11 is formed at each tip portion of the mounting surface 11, thus preventing the work unit from falling off the mounting surface 11. Further, a stepped portion 13 having a surface more elevated than the mounting surface 11 is formed at a rear side of the mounting surface 11, thus limiting an extent of misalignment of the work unit mounted to the mounting surface 11. In order to facilitate the mounting of the work unit to the above-described mounting surface 11 of the robot hand 10, the mounting surface 11 is formed larger than the diameter of the work unit. As a result, the work unit can move more or less in a horizontal direction parallel to the mounting surface 11 when mounted to the mounting surface 11.
The conventional robot hand configured as described above can, for example, extract the work unit from the cassette and transport it to the temporary storage table before transporting it to the processing table. Further, after the plate-shaped work making up the work unit is processed by the processor, the robot hand can transfer the work unit from the processing table to the cleaning table. Further, the robot hand can unload the work unit that has been cleaned and dried on the cleaning table from the cleaning table and store it in the cassette (refer, for example, to Japanese Patent Laid-Open Nos. 2011-035281 and 2011-131284).